15x21x4 Ceramic Rubber Sealed Ball Bearing for RC Cars 6702-2RSC 15x21x4 Ceramic Rubber Sealed Bearing 6702-2RSC RC Car Kit contains all upgraded Ceramic bearings to replace your stock factory bearings and bushings. ABEC rated with Ceramic Balls, Hi-temperature, low drag lubrication. Maintenance free rubber seals to keep the contamination out and the grease in. Complete Ceramic Ball Bearing Kits are custom packaged for your vehicle. Genuine FastEddy Bearings, The most trusted name in RC Bearings. New Ceramic FastEddy Bearings will allow your RC to run faster and longer then old worn out bearings.